Calling all KSP Pro's I Require assitance

[Dermeister]

SO i built this shuttle it launches fine. When i booster Sep the noze dives into an uncontrolable spin. I need viable ideas and solutions! I tried damn robotics for a gimble but they are to obig and don't work well for my current engine! I want to try to keep this engine if possible because it has just enough power and weight for the rentry and landing phases( the 2 air breathing engines) the Main engine has 1200 KTU's of thrust just enough to stop me from rollign back when the booster are at full power and low on fuel. So i don't want to go with smaller engines for the MAIN engine. Or do i? I don't know what to do at this point i tried moving the fuel tank( middle tank attached under the belly) Up and down to see if it changed my centre of mass enough. i tried smaller/Bigger fuel tank. Any mods or ideas? or better engine gimbals than damn robotics?

P.S sory for the small Picture the forums are not letting me upload it for some reason and yes i checked the jpg file size.

Edited May 4, 2013 by Dermeister

[Trux]

The picture is a little small

[Dermeister]

The picture is a little small

I know but as i wrote i nthe P.S ... do you have a solution for the small pic? i tried to upload a bigger 1 but my album keeps giving me an error when i try to upload.

[Naiba]

Have you thought about adding radial engines to the far side of your main fuel droptank? You could set them to fire after your boosters separate and keep it balanced against your ship's main engines till the fuel's gone and you can ditch it.

*Try uploading to something like imageshack.us first, then posting it with

Edited May 4, 2013 by Naiba

[Dermeister]

Thanks for the reply! And yes i tired that.. Unfortunatly it dosent help i think its the initial jolt of the change of COM(Center of mass) and the time it takes to fire the Radials. Stand by i'm Imageshackign it now.

ANdi tried cuttign the engines... i think it needs S.A.S which i will try.. alot of SAS under the fuel tank.. to hopfully torque it to stay straight... or ineed to fidn agood gimbal mod or soem genious Sguys in aerodynamics! to tel lem where to moove the tank for stability >_<! but picture is going to be posted soon stanf by i evne included thje COM AND COT ect in it

Edited May 4, 2013 by Dermeister

[Naiba]

You could try and cut the main engines with X just as the boosters run out of fuel, should give you a few seconds to get things in order before loosing too much speed.

* Hmm... tricky one then, classic 'space shuttle' layouts on rockets have always been notoriously difficult to keep balanced. ASAS will certainly help you a little. What hight do your boosters run dry and how many engines do you have on the main ship?

Edited May 4, 2013 by Naiba

[Dermeister]

OK image uploaded if you guys want ican take a pic without the boosters. so u can see what happend to the COT and COM

[Naiba]

Is the shuttle itself balanced without the tank and boosters?

[Dermeister]

You could try and cut the main engines with X just as the boosters run out of fuel, should give you a few seconds to get things in order before loosing too much speed.

* Hmm... tricky one then, classic 'space shuttle' layouts on rockets have always been notoriously difficult to keep balanced. ASAS will certainly help you a little. What hight do your boosters run dry and how many engines do you have on the main ship?

I have 1 main engine that runs and 2 lil 33 thrust ones for orbital manuvering those are on just extra gimbalage but they don't help anythign icould leave them on they are insiginificant compared to the whopping 1200 Ktu's of thrust the main engines do!

[Dermeister]

Yes its a bit Low on pitch auhority but it glides well at a noze down angle of - 5 Deg it needs the Air engines to land safe though because if you flare you get too slow and at those slow speeds theres not enough lift but i dint want ot have to much lift as to not upset the VL of the whole thing.

Is the shuttle itself balanced without the tank and boosters?

[MRab2]

You're going to need radial engines on the far side of the main fuel tank. There's no question. I Personally would start with one near the nose and angled outwards at maybe 30 degrees. After that it should be fine tuning.

[Dermeister]

I shal ltry now you mean liek on the back of the tank near top top or bottom? i wish some 1 made agood tutorial on how to build a system like this.

[MRab2]

I shal ltry now you mean liek on the back of the tank near top top or bottom? i wish some 1 made agood tutorial on how to build a system like this.

I mean at the top of the tank. Without seeing how it performs I can't be particularly specific. But basically, your nose is pitching down so you want a counter force at the nose to prevent this. Now, you *might* get away with winglets but I personally doubt it. In my experience winglets are best used on a fairly stable stable to prevent the slight build up of imbalances (fuel lines and such that can start to become a drama at higher speeds whilst deep in the atmosphere). Using them on a system that's inherently unstable rarely works - especially once the atmosphere starts to thin.

Anyway, another motor behind the nose, liberally quantities of RCS and ASAS and you should be fine.

[Dermeister]

Thanks for the tips i'm goign to try them also! just so you know it's not easy because thing thing aloen with out boosters and fuel tank has a mass of almost 60

[Shuttle]

I created a thread about how to build a shuttle with tips, crafts and screenshots about half a year ago but it is gone. The only thing I have left is screenshots and craft file:

I built two vanilla shuttles that can achieve 100*100 km orbit and go back easily. Your shuttle flips because booster engines and shuttle engines are not in the center of mass => they create rotating moment. When shuttle is launched, those rotating moments are compensated but when the boosters are dropped, the rotating moment from the shuttle's engines is no longer compensated => it flips over.

Could you, please, provide a screenshot of your shuttle from different angle? I don't understand if there are any engines on the central fuel tank.

[MRab2]

To Shuttle: Would I be right in saying that fuel is being fed from the main tank to the shuttle?

[Shuttle]

MRab2, yes, in both of my shuttles fuel is fed from the main tank to shuttle even after boosters are separated.

[Dermeister]

I created a thread about how to build a shuttle with tips, crafts and screenshots about half a year ago but it is gone. The only thing I have left is screenshots and craft file:

I built two vanilla shuttles that can achieve 100*100 km orbit and go back easily. Your shuttle flips because booster engines and shuttle engines are not in the center of mass => they create rotating moment. When shuttle is launched, those rotating moments are compensated but when the boosters are dropped, the rotating moment from the shuttle's engines is no longer compensated => it flips over.

Could you, please, provide a screenshot of your shuttle from different angle? I don't understand if there are any engines on the central fuel tank.

NIce looks liek you put an engine under the main fuel tank though ... intrestign i thought of doign so myself... but now ithink i devised asystem that works.. if it does ill take screenys till then Keep sugestions coming it's much appriciated and it gives me ideas

[Ariellus]

Is the engine of the shuttle build out of 3 similar engines or is it one engine ?

Do you know that you can build engines IN girders with alt+f12 and deactivating clipping ?

This way you can set the upper engine 5 degrees to up and after tank seperation you could deactivate it with actiongroups and only fly with the last two of them.

+ you use atmospheric engines the shuttle was a glider (i think the buran too)

Cut the atmospheric engines and build some very small engines 5 degrees upward the mainengines of the shuttle should stay as they are, then you can use the smaller engines to counter the nosedive and cut them with actionsgroups after tank seperation.

If you are using firespitter addon you can try to build one or 2 airbrakes finecontrolled by actiongroups on the other side of the fueltank to counter it (extend them a little bit and they should push you the other way without loosing to much speed)

I use the firespitter aerobrakes alot at the upper end of the rudder on airplanes to bring the nose up

Edited May 4, 2013 by Ariellus

[Dermeister]

Is the engine of the shuttle build out of 3 similar engines or is it one engine ?

Do you know that you can build engines IN girders with alt+f12 and deactivating clipping ?

This way you can set the upper engine 5 degrees to up and after tank seperation you could deactivate it with actiongroups and only fly with the last two of them.

+ you use atmospheric engines the shuttle was a glider (i think the buran too)

Cut the atmospheric engines and build some very small engines 5 degrees upward the mainengines of the shuttle should stay as they are, then you can use the smaller engines to counter the nosedive and cut them with actionsgroups after tank seperation.

If you are using firespitter addon you can try to build one or 2 airbrakes finecontrolled by actiongroups on the other side of the fueltank to counter it (extend them a little bit and they should push you the other way without loosing to much speed)

I use the firespitter aerobrakes alot at the upper end of the rudder on airplanes to bring the nose up

Nice ideas and i use 1 Engine thath as 3 nozels. the atmospheric enginesi coudl try to switch.. but as it stands i kinda need them to land >_> lolcause the thign has alot of drag due to ksp not taking for accoutn stuff is in fairings or cargo bays ect. so when i pull up to flare for landing... i stall out thus why i have those engines . it flys great though while re entering up untill your near the runway it glides then.... it runs out of energy quick as you pull up to land and you stall. Those engines fix that i might try multiple engines like you said sugestions appriciated

[Ariellus]

btw http://kerbalspaceprogram.com/draktec-vtol-engines/ this could help too with some small engines build 4 of the orange radial engines at the lower end of the tank and with rightclick or actiongrp set them in rcs mode then you dont need to change anything

[Dermeister]

Thank you ill check it out

[Shuttle]

NIce looks liek you put an engine under the main fuel tank though ... intrestign i thought of doign so myself... but now ithink i devised asystem that works.. if it does ill take screenys till then Keep sugestions coming it's much appriciated and it gives me ideas

Yes, it allows to balance the shuttle after boosters separation.

[Dermeister]

Yes, it allows to balance the shuttle after boosters separation.

I'm giving up i tried everythign S.A.S, Angeled engines no matterh ow i angle its either too much or not enough on the gimbal, I tried moving the boosters aroudn tank up tank down... I simply cannot get a 2 booster+ belly tank system to work... i cna get it to work on lift off but then as the fuel emptys the shuttle pitches back... when you sep booster the noze pitches foward liek mad... if i angle the Engines at the back with a gimbal to counter the foward pitch.. it pitches bakc with the boosters.... if i don't gimbal the engines back it pitches foward at booster sep... if some 1 can ballance my shuttle Props to you. I'm going to give up on this design and keep checkign this thread to see if any 1 has aworking solution or ideas ! i really want to get this design to work I evne googled how they did it in Real life for the shuttle lol funny enough they don't go into technical stuff too much.. just basics that i allready knew

[MRab2]

Post the save file somewhere. I'll have a look at it.